docs: def _compute_anom_score(self, lag_window_points, point):
          """
          Compute anomaly score for a single data point.
          Anomaly score for a single data point(t,v) equals: abs(v - ema(lagging window)).
          :param list lag_window_points: values in the lagging window.
          :param float point: data point value.
          :return float: the anomaly score.
          """
          ema = utils.compute_ema(self.smoothing_factor, lag_window_points)[-1]
          return abs(point - ema)